Electrospinning of Gelatin Functionalized with Silver Na-noparticles for Nanofiber Fabrication

Abstract

The present paper deals with gelatin nanofibres functionalized with\rsilver nanoparticles, prepared by electrospinning using solutions of gelatin mixed with silver nitrate (AgNO3).\rAs a common solvent for gelatin and silver nitrate (AgNO3), a mixture\rof acetic acid and water (70:30 v/v) was selected. In this system, acetic acid was\rused as a solvent for gelatin, and at the same time reducing agent for silver ions\rin solution. Silver nanoparticles (nAg) were stabilized through a mechanism\rthat involves an interaction of the oxygen atoms of the carbonyl groups of\rgelatin. The viscosity and the conductivity of the gelatinous solutions were\rfound to increase with the solution concentration. There is an observed decrease in the viscosity of the nAg containing gelatin solutions with\rthe aging time increasing, whereas the conductiity of the AgNO3—containing\rgelatin solutions was greater than that of the base gelatin solution. The\rgelatin nanofibres functionalized with silver nanoparticles were characterized\rby transmission electron microscopy (TEM), scanning electron microscopy (SEM),\rX-ray diffraction (XRD) and antimicrobial test. The results of investigations\rby TEM and XRD confirmed the presence of silver nanoparticles with diameters in\rthe range of (2 - 10 nm), uniformly distributed over the surface of smooth nanofibres\rwith an average diameter of 70 nm. The release of silver ions from both the 2-\rand 4-hrs crosslinked nAg containing gelatin fiber mats by a total immersion\rmethod in buffer and distilled water occurred rapidly during the first 60 minutes, and\rincreased gradually afterwards. Lastly, the tests demonstrated that gelatin/Ag\rnanofibers have a good antimicrobial activity against some common bacteria\rfound on burned wounds. The anti-bacterial activity of these materials was\rgreatest against Staphylococcus aureus, followed by Escherichia coli, and Pseudomonas aeroginosa ≈\rCandida albicans.